The present invention relates to housings, particularly module carriers, including supporting rails to accommodate a plurality of mutually parallel guide rails in which plug-in units can be inserted which are equipped with electronic and electrical components, with unoccupied plug-in locations being covered by a covering.
In housings, particularly module carriers, for plug-in units which are equipped with electronic and electric components, it is necessary to carry away the heat discharged by the components. This heat can be carried away by natural convection, possibly supported by blowers, heat exchangers or cooling devices. In any case, it is important for the incoming air to flow as closely as possible along the circuit boards equipped with the components. If not all plug-in locations are occupied, a less favorable flow of air results for the inserted plug-in components than would be the case if all of the plug-in locations were occupied. The reason for this is the more favorable flow resistances of the unoccupied spaces compared to the spaces occupied by plug-in units.
It is already known to consider the above-described problems by covering the unoccupied plug-in locations with the aid of appropriately shaped fixed cover plates. However, such fixed cover plates are relatively expensive special components which must be manufactured especially for the respective application. Subsequent changes of the plug-in location occupation pattern are rather expensive to accomplish and generally require the installation of matching cover plates.